1. Field of the Invention
The present invention relates to a tube for the circulation of a flammable fluid, as well as to a conduit made from such tubes.
2. Background Art
The invention is particularly, but not exclusively, applicable to the tubes for the circulation of fuel in aircraft of which numerous structures, such as the tanks, are made at least partially of insulating composite material.
When a metallic fuel circuit is installed in a totally or partially insulating structure, such as a fuel tank made of composite material, and when said structure is struck by lightning, a considerable current of lightning risks circulating in the conduit which is a better conductor of electricity than the surrounding structure. This phenomenon presents considerable risks due to overheating or to sparks which may be produced at the different joints between conduit elements, during passage of the current.
Furthermore, the conduit of the fuel circuit must satisfy two requirements. The first is that of withstanding the mechanical efforts produced by the fuel or the deformations of the structure in which it is mounted. The second is that of evacuating the static electricity created by the circulation of the fuel - electrically insulating - at high speed in the conduit. These two functions are generally ensured when the tube is made of metal, which, on the other hand, presents, as has been seen hereinabove, risks in the event of the aircraft being struck by lightning.